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Environmental Radiation Control

For handling of uranium, appropriate radiation protection is provided to secure environmental safety as follows,

  • continuous monitoring of radiation with monitoring posts at the site boundary,
  • well removing radioactive substance from such exhaust and effluent from the plant,
  • continuous monitoring of their radioactivities to confirm them to be within discharge criteria.

Environmental monitoring data

Environmental radiation at the site boundary of Mitsubishi Nuclear Fuel (MNF) plant at Tokai is continuously monitored.

The gamma-ray dose rate at the plant compound surveillance zone boundary is continuously measured in microGrays per hour (μGy/hr). During a rainfall, naturally existing radioactive material will be concentrated on the ground and the measurement will be temporarily elevated. The normal range of the dose rate is about 0.03 to 0.10 μGy/hr.
If the dose rate exceeds the set value, the monitor gives out alarm.

Emission control

The exhaust which is discharged from our plant to the environment is continuously monitored for the level of radioactivity.

Dust emission monitor

  • The radioactivity concentration in the exhaust is continuously measured.

Emission control

Dust water quality analyses

By measuring the radioactivity concentration (Bq/cc) in the discharge water and accounting for the discharge volume at that time, the amount of radioactivity can be calculated.

The liquid effluent which is discharged from our plant is is periodically analyzed to assure that both the radioactive concentration and amounts are within expected levels.